626 THE STRUCTURE OF EVOLUTIONARY THEORY
an afterthought, the vehicle concept is tacked onto the edifice to reflect the
harmonious organization of individuals, but it is not extended to the level of
groups."
The central problem lies as deep as our definition of the key concept of
"cause" in science. Aristotle proposed a broad concept of causality divided into
four aspects, which he called material, efficient, formal and final (or, roughly,
stuff, action, plan and purpose—that is, the bricks, the mason, the blueprint and the
function, in the standard "parable of the house," used for more than two millennia
to explicate Aristotle's concept). As many historians have noted, modern science
may virtually be defined by a revision of this broad view, and a restriction of
"cause," as a concept and definition, to the aspect that Aristotle called "efficient."
(The word "efficient" derives from the Latin facere, to make or to do. Efficient
causes are actual movers and shakers, the agents that apply the forces. Aristotle's
term does not engage the modern English meaning of doing something well, as
opposed to doing something at all.)
The Cartesian or Newtonian worldview, the basis of modern science, banned
final cause for physical objects (while retaining the concept of purpose for
biological adaptation, so long as mechanical causes, rather than conscious external
agencies, could be identified—a problem solved by natural selection in the 19th
century). As for Aristotle's material and formal causes, these notions retained their
relevance, but lost their status as "causes" under a mechanical worldview that
restricted causal status to active agents. The material and formal causes of a house
continue to matter: brick or sticks fashion different kinds of buildings, while the
bricks just remain in a pile, absent a plan for construction. But we no longer refer
to these aspects of building as "causes." Material and formal attributes have
become background conditions or operational constraints in the logic and
terminology of modern science.
I present this apparent digression because the chief error of gene selectionism
lies in a failed attempt to depict genes as efficient causes in ordinary natural
selection—and the chief "textual mark" of failure can be located in tortuous and
clearly discomforting (even to the authors!) arguments advanced by all leading
gene selectionists in a valiant struggle to "get through" this impediment. For no
matter how an author might choose to honor genes as basic units, as carriers of
heredity to the next generation, as faithful replicators, or whatever, one cannot
deny a fundamental fact of nature: in ordinary, garden-variety natural selection—
Darwin's observational basis and legacy—organisms, and not genes, operate as the
"things out there" that live and die, reproduce or fail to propagate, in the interaction
with environments that we call "natural selection." Organisms act as Aristotle's
efficient causes—the actors and doers—in the standard form of Darwin's great and
universal game.
Gene selectionists know this, of course—so they must then struggle to
construct an argument for saying that, even though organisms do the explicit work,
genes may somehow still be construed as primary "units of selection,"